path: root/tools/testing/selftests/livepatch
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2019-11-27 11:42:01 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-11-27 11:42:01 -0800
commit95f1fa9e3418d50ce099e67280b5497b9c93843b (patch)
treeb8617e471a9b9993ac1bad48e2d954335f8a6232 /tools/testing/selftests/livepatch
parentMerge tag 'microblaze-v5.5-rc1' of git://git.monstr.eu/linux-2.6-microblaze (diff)
parenttracing: Enable syscall optimization for MIPS (diff)
Merge tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: "New tracing features: - New PERMANENT flag to ftrace_ops when attaching a callback to a function. As /proc/sys/kernel/ftrace_enabled when set to zero will disable all attached callbacks in ftrace, this has a detrimental impact on live kernel tracing, as it disables all that it patched. If a ftrace_ops is registered to ftrace with the PERMANENT flag set, it will prevent ftrace_enabled from being disabled, and if ftrace_enabled is already disabled, it will prevent a ftrace_ops with PREMANENT flag set from being registered. - New register_ftrace_direct(). As eBPF would like to register its own trampolines to be called by the ftrace nop locations directly, without going through the ftrace trampoline, this function has been added. This allows for eBPF trampolines to live along side of ftrace, perf, kprobe and live patching. It also utilizes the ftrace enabled_functions file that keeps track of functions that have been modified in the kernel, to allow for security auditing. - Allow for kernel internal use of ftrace instances. Subsystems in the kernel can now create and destroy their own tracing instances which allows them to have their own tracing buffer, and be able to record events without worrying about other users from writing over their data. - New seq_buf_hex_dump() that lets users use the hex_dump() in their seq_buf usage. - Notifications now added to tracing_max_latency to allow user space to know when a new max latency is hit by one of the latency tracers. - Wider spread use of generic compare operations for use of bsearch and friends. - More synthetic event fields may be defined (32 up from 16) - Use of xarray for architectures with sparse system calls, for the system call trace events. This along with small clean ups and fixes" * tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (51 commits) tracing: Enable syscall optimization for MIPS tracing: Use xarray for syscall trace events tracing: Sample module to demonstrate kernel access to Ftrace instances. tracing: Adding new functions for kernel access to Ftrace instances tracing: Fix Kconfig indentation ring-buffer: Fix typos in function ring_buffer_producer ftrace: Use BIT() macro ftrace: Return ENOTSUPP when DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not configured ftrace: Rename ftrace_graph_stub to ftrace_stub_graph ftrace: Add a helper function to modify_ftrace_direct() to allow arch optimization ftrace: Add helper find_direct_entry() to consolidate code ftrace: Add another check for match in register_ftrace_direct() ftrace: Fix accounting bug with direct->count in register_ftrace_direct() ftrace/selftests: Fix spelling mistake "wakeing" -> "waking" tracing: Increase SYNTH_FIELDS_MAX for synthetic_events ftrace/samples: Add a sample module that implements modify_ftrace_direct() ftrace: Add modify_ftrace_direct() tracing: Add missing "inline" in stub function of latency_fsnotify() tracing: Remove stray tab in TRACE_EVAL_MAP_FILE's help text tracing: Use seq_buf_hex_dump() to dump buffers ...
Diffstat (limited to 'tools/testing/selftests/livepatch')
6 files changed, 95 insertions, 13 deletions
diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile
index 1cf40a9e7185..3876d8d62494 100644
--- a/tools/testing/selftests/livepatch/Makefile
+++ b/tools/testing/selftests/livepatch/Makefile
@@ -5,6 +5,7 @@ TEST_PROGS := \
test-livepatch.sh \
test-callbacks.sh \
test-shadow-vars.sh \
- test-state.sh
+ test-state.sh \
+ test-ftrace.sh
include ../lib.mk
diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
index 79b0affd21fb..31eb09e38729 100644
--- a/tools/testing/selftests/livepatch/functions.sh
+++ b/tools/testing/selftests/livepatch/functions.sh
@@ -29,29 +29,45 @@ function die() {
exit 1
-function push_dynamic_debug() {
- DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \
- awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')
+function push_config() {
+ DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \
+ awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')
+ FTRACE_ENABLED=$(sysctl --values kernel.ftrace_enabled)
-function pop_dynamic_debug() {
+function pop_config() {
if [[ -n "$DYNAMIC_DEBUG" ]]; then
echo -n "$DYNAMIC_DEBUG" > /sys/kernel/debug/dynamic_debug/control
+ if [[ -n "$FTRACE_ENABLED" ]]; then
+ sysctl kernel.ftrace_enabled="$FTRACE_ENABLED" &> /dev/null
+ fi
-# set_dynamic_debug() - save the current dynamic debug config and tweak
-# it for the self-tests. Set a script exit trap
-# that restores the original config.
function set_dynamic_debug() {
- push_dynamic_debug
- trap pop_dynamic_debug EXIT INT TERM HUP
cat <<-EOF > /sys/kernel/debug/dynamic_debug/control
file kernel/livepatch/* +p
func klp_try_switch_task -p
+function set_ftrace_enabled() {
+ local sysctl="$1"
+ result=$(sysctl kernel.ftrace_enabled="$1" 2>&1 | paste --serial --delimiters=' ')
+ echo "livepatch: $result" > /dev/kmsg
+# setup_config - save the current config and set a script exit trap that
+# restores the original config. Setup the dynamic debug
+# for verbose livepatching output and turn on
+# the ftrace_enabled sysctl.
+function setup_config() {
+ push_config
+ set_dynamic_debug
+ set_ftrace_enabled 1
+ trap pop_config EXIT INT TERM HUP
# loop_until(cmd) - loop a command until it is successful or $MAX_RETRIES,
# sleep $RETRY_INTERVAL between attempts
# cmd - command and its arguments to run
diff --git a/tools/testing/selftests/livepatch/test-callbacks.sh b/tools/testing/selftests/livepatch/test-callbacks.sh
index e97a9dcb73c7..a35289b13c9c 100755
--- a/tools/testing/selftests/livepatch/test-callbacks.sh
+++ b/tools/testing/selftests/livepatch/test-callbacks.sh
@@ -9,7 +9,7 @@ MOD_LIVEPATCH2=test_klp_callbacks_demo2
# TEST: target module before livepatch
diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh
new file mode 100755
index 000000000000..e2a76887f40a
--- /dev/null
+++ b/tools/testing/selftests/livepatch/test-ftrace.sh
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2019 Joe Lawrence <joe.lawrence@redhat.com>
+. $(dirname $0)/functions.sh
+# TEST: livepatch interaction with ftrace_enabled sysctl
+# - turn ftrace_enabled OFF and verify livepatches can't load
+# - turn ftrace_enabled ON and verify livepatch can load
+# - verify that ftrace_enabled can't be turned OFF while a livepatch is loaded
+echo -n "TEST: livepatch interaction with ftrace_enabled sysctl ... "
+dmesg -C
+set_ftrace_enabled 0
+load_failing_mod $MOD_LIVEPATCH
+set_ftrace_enabled 1
+if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then
+ echo -e "FAIL\n\n"
+ die "livepatch kselftest(s) failed"
+set_ftrace_enabled 0
+if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then
+ echo -e "FAIL\n\n"
+ die "livepatch kselftest(s) failed"
+disable_lp $MOD_LIVEPATCH
+unload_lp $MOD_LIVEPATCH
+check_result "livepatch: kernel.ftrace_enabled = 0
+% modprobe $MOD_LIVEPATCH
+livepatch: enabling patch '$MOD_LIVEPATCH'
+livepatch: '$MOD_LIVEPATCH': initializing patching transition
+livepatch: failed to register ftrace handler for function 'cmdline_proc_show' (-16)
+livepatch: failed to patch object 'vmlinux'
+livepatch: failed to enable patch '$MOD_LIVEPATCH'
+livepatch: '$MOD_LIVEPATCH': canceling patching transition, going to unpatch
+livepatch: '$MOD_LIVEPATCH': completing unpatching transition
+livepatch: '$MOD_LIVEPATCH': unpatching complete
+modprobe: ERROR: could not insert '$MOD_LIVEPATCH': Device or resource busy
+livepatch: kernel.ftrace_enabled = 1
+% modprobe $MOD_LIVEPATCH
+livepatch: enabling patch '$MOD_LIVEPATCH'
+livepatch: '$MOD_LIVEPATCH': initializing patching transition
+livepatch: '$MOD_LIVEPATCH': starting patching transition
+livepatch: '$MOD_LIVEPATCH': completing patching transition
+livepatch: '$MOD_LIVEPATCH': patching complete
+livepatch: sysctl: setting key \"kernel.ftrace_enabled\": Device or resource busy kernel.ftrace_enabled = 0
+% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled
+livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
+livepatch: '$MOD_LIVEPATCH': starting unpatching transition
+livepatch: '$MOD_LIVEPATCH': completing unpatching transition
+livepatch: '$MOD_LIVEPATCH': unpatching complete
+% rmmod $MOD_LIVEPATCH"
+exit 0
diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh
index f05268aea859..493e3df415a1 100755
--- a/tools/testing/selftests/livepatch/test-livepatch.sh
+++ b/tools/testing/selftests/livepatch/test-livepatch.sh
@@ -7,7 +7,7 @@
# TEST: basic function patching
diff --git a/tools/testing/selftests/livepatch/test-shadow-vars.sh b/tools/testing/selftests/livepatch/test-shadow-vars.sh
index 04a37831e204..1aae73299114 100755
--- a/tools/testing/selftests/livepatch/test-shadow-vars.sh
+++ b/tools/testing/selftests/livepatch/test-shadow-vars.sh
@@ -6,7 +6,7 @@
# TEST: basic shadow variable API